scholarly journals Fast-Hardening Foam: Fire and Explosion Prevention at Facilities with Hazardous Chemicals

2017 ◽  
Vol 6 (4) ◽  
pp. 56
Author(s):  
Gennady N. Kuprin ◽  
Denis S. Kuprin
Keyword(s):  
Acetic Acid ◽  
Hydrogen Chloride ◽  
Hydrogen Fluoride ◽  
Diesel Fuel ◽  
High Probability ◽  
Hydrogen Bromide ◽  
Screening Method ◽  
Hazardous Chemicals ◽  
Experimental Apparatus ◽  
Fire And Explosion

Analysis of the terroristic attacks in Siria, Afghanistan and other countries has shown high probability of the hazardous chemicals application by the terroristic groups. In the article the most catastrophic accidents which were connected with hazardous chemicals are described.That is why research and developments in the sphere of protection from hazardous chemicals are still actual.This article is dedicated to the new screening method of the spilled hazardous chemicals surface on the example of protection of the factories with these substances. Methodology, experimental apparatus, protective fast-hardening foam features, names of hazardous chemicals are shown.Test were made for such chemicals as: acetic acid, acetone, ammonia, bromine, chlorbenzene, chloroform, hydrogen bromide, hydrogen chloride, hexane, hydrazine, diesel fuel, dichlorethane, kerosene, toluene, phenol, hydrogen fluoride. Fantastic results were achieved in terms of isolating capability of the fast-hardening foam against evaporations of the pointed substances.

Peptide syntheses with the 2,4,6-trimethylbenzyl esters of L-asparagine and L-glutamine

1967 ◽  
Vol 20 (2) ◽  
pp. 365 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Acetic Acid ◽  
Amino Acid ◽  
Hydrogen Chloride ◽  
Hydrogen Bromide ◽  
Amino Acid Esters ◽  
Mild Conditions ◽  
Acid Esters

The 2,4,6-trimethylbenzyl esters of L-asparagine and L-glutamine have been obtained as the crystalline hydrochlorides by treatment of the o- nitrophenylsulphenyl amino acid esters with methanolic hydrogen chloride. These hydrochlorides were used in the synthesis of several benzyloxycarbonyl peptide 2,4,6-trimethylbenzyl esters, which were converted into the corresponding free peptides by the action of hydrogen bromide in acetic acid under mild conditions.

The use of 2,4,6-trimethylbenzyl esters in peptide synthesis

1966 ◽  
Vol 19 (6) ◽  
pp. 1067 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Acetic Acid ◽  
Hydrogen Chloride ◽  
Peptide Synthesis ◽  
Hydrogen Bromide ◽  
Ester Group ◽  
Protecting Groups ◽  
Reaction Conditions ◽  
Model Experiments ◽  
Benzyl Esters

Model experiments with the 2,4,6-trimethylbenzyl esters of N-acylamino acids have shown that this ester group is cleaved by hydrogen bromide in acetic acid under reaction conditions which do not affect benzyl esters appreciably, but which result in removal of benzyloxycarbonyl amino-protecting groups. 2,4,6-Trimethyl- benzyl esters, however, are unaffected by methanolic hydrogen chloride under the conditions used to cleave o-nitrophenylsulphenyl and trityl protecting groups. These selective differences have been utilized for the synthesis of various benzyloxycarbonyl peptide 2,4,6-trimethylbenzyl esters up to the hexapeptide level. Some of these derivatives have been converted into the corresponding free peptides by the action of hydrogen bromide in acetic acid. The 2,4,6-trimethylbenzyl group is more readily cleaved by hydrogen bromide than p-nitrobenzyloxycarbonyl and the possible application of this situation to peptide synthesis is considered.

Cyclohexane compounds. VII. Nucleophilic scission of the stereoisomeric 3-methoxycyclohexene oxides

1968 ◽  
Vol 46 (1) ◽  
pp. 35-42 ◽  
Author(s):  
R. A. B. Bannard ◽  
A. A. Casselman ◽  
E. J. Langstaff ◽  
R. Y. Moir
Keyword(s):  
Acetic Acid ◽  
Hydrogen Chloride ◽  
Vapor Phase ◽  
Inductive Effect ◽  
Hydrogen Bromide ◽  
Transition States ◽  
Product Distributions ◽  
Steric Factors ◽  
Alkaline Conditions ◽  
Cis And Trans

The mode of scission of cis- and trans-3-methoxycyclohexene oxides by hydrogen chloride, hydrogen bromide, ammonia, acetic acid, and methanol (under both acidic and alkaline conditions) has been examined using vapor-phase chromatography to detect and isolate minor isomers. Approximately 10% of the product from opening of the trans oxide is formed by attack at position-2 with each of these nucleophiles, whereas opening of the cis oxide proceeds exclusively by attack at position-1. The results are interpreted as reflecting very similar transition states for all of these reactions, with differences in product distributions for the two oxides being governed by the inductive effect of the methoxyl group and by steric factors in the corresponding transition states.

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